Investigators from the University of Michigan School of Nursing in Ann Arbor examined the effects of using our Healthful Sleep guided imagery on post-cardiac surgery sleep disturbances (problems with sleep quality, time taken to fall asleep and total sleep time) and systemic inflammatory response, as measured by stress hormones and inflammatory markers, including cortisol and C-reactive proteins.  These post-surgical difficulties are exacerbated when a patient is put on a bypass machine, and are predictors of post-op morbidity and mortality.

Of the 52 patients who provided informed consent, 27 were randomly assigned to the guided imagery group and 25 to usual care only during the ICU and step-down phases of post-op recovery.  Of these, 5 in each group were lost to follow-up.

Patients were provided with MP3 players preloaded with Healthful Sleep; SleepPhones (a fleece headband with built in speakers worn over both ears) and spare batteries.  

The imagery was administered by the nurse between 10 pm and midnight and left on the nightstand for when the patient woke up during the night. Patients rated how well they liked the intervention, and sleep efficiency was measured by a wrist actigraph (ActiWatch).  Salivary cortisol and C-RP measures were taken between 6-8 am the following morning. Pain and anxiety levels were also rated.

Patients in the guided imagery group had consistently better sleep quality, more total sleep time, and took less time to fall asleep; and these improvements increased over time. Additionally, the guided imagery patients enjoyed a greater decline in inflammation over time, as measured by cortisol levels and C-reactive proteins. But the findings fell just short of significance. The patients liked the imagery and felt it helped them. Large scale studies are needed to establish conclusive evidence of the value of guided imagery for sleep and inflammation; in the meantime, the researchers conclude that imagery should complement other methods to promote sleep in hospitalized patients.

Citation: Casida JM, Yaremchuk KL, Shpakoff L, Marrocco A, Babicz G, Yarandi H. The effects of guided imagery on sleep and inflammatory response in cardiac surgery: a pilot randomized controlled trial.  Journal of Cardiovascular Surgery (Torino). 2013 Apr; 54 (2): pp 269-79. Epub 2012 Nov 9. [email protected]